Prove that all triangles obc are equal to oad

So oc = op, BC = AP

Because the angle COP = 90 degrees

So CP = radical 2po

So Pb-pa/po = Pb-PC/po = PC/po = root number 2.

2. Solution: Angle OAC = 90°, even ae, af, ef.

Prove that aof of triangle is equal to aoc.

So ce = of

So OE-of = OE-CE = OC = root number 2ao = 2 times root number 2.